This took forever to get right, but all my filament dryboxes are at 10% and I can’t get it any lower.
this post was submitted on 04 Apr 2026
189 points (99.0% liked)
3DPrinting
22575 readers
2 users here now
3DPrinting is a place where makers of all skill levels and walks of life can learn about and discuss 3D printing and development of 3D printed parts and devices.
The r/functionalprint community is now located at: or !functionalprint@fedia.io
There are CAD communities available at: !cad@lemmy.world or !freecad@lemmy.ml
Rules
-
No bigotry - including racism, sexism, ableism, homophobia, transphobia, or xenophobia. Code of Conduct.
-
Be respectful, especially when disagreeing. Everyone should feel welcome here.
-
No porn (NSFW prints are acceptable but must be marked NSFW)
-
No Ads / Spamming / Guerrilla Marketing
-
Do not create links to reddit
-
If you see an issue please flag it
-
No guns
-
No injury gore posts
If you need an easy way to host pictures, https://catbox.moe/ may be an option. Be ethical about what you post and donate if you are able or use this a lot. It is just an individual hosting content, not a company. The image embedding syntax for Lemmy is 
Moderation policy: Light, mostly invisible
founded 2 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
If there's moisture in the filament it vaporises in the extruder, causing steam bubbles that expand and disrupt the laying down of plastic, usually causing inconsistent extrusion lines (which itself causes poor layer adhesion). Some of the filament may end up being heated in the extruder slightly longer than other bits depending on these steam bubbles, which can cause overheating issues like stringing and oozing, etc..
Not to mention that filament that has absorbed water tends to become more brittle, which can lead to the filament snapping off before reaching the extruder. As a result, a filament's shelf-life is usually dictated by how quickly it absorbs moisture (and also whether UV from the sun weakens it at all, but that's a lot easier to manage).
Brittleness didn't get talked about enough. I couldn't figure out why my fundament was breaking on retraction to my Creality Hi CFS over and over again. It was driving me nuts. The prints all came out looking great, so I thought I wasn't having humidity issues and that there was a mechanical problem somewhere. Took the whole damn thing apart to clean and check that everything was tightened to correctly. Multiple times.
I just needed a filament dryer.
I had no idea that filament snapping on retraction could be caused by wet filament, and I read about 3D printing a lot more than most. Almost all threads about wet filament are about print quality, and people rarely mention brittleness. Conversely, in threads about filament jams/errors, most comments focus on the mechanical parts (tension, loose screws, debris in the gears, temps, etc.) and rarely mention wet, brittle filament as a possible cause.
If you're reading this and don't have one (or another method for it), get a filament dryer. I recommend the Creality one when it goes on sale as it's one of the cheapest options that can hit the high temps needed for some filaments and that can also be used as a dry box you can print from. My only gripe is needing to prop the lid open when it's drying to release the humidity. It's silly that it can't dry filament properly without the door cracked open.